422 dyno fail

[rumblefish360]

Sounds like is a nice street engine build. I wouldn’t worry about the low numbers the dyno jet kicked out since it’s at the rear wheels. As noted, the drive train eats up a bunch of power with the transmission being a hungry SOB no matter the model. Power is lost all the way to the wheels. Driveshaft, rear gears, axles and tires. Everything is eating some power.

If that engine itself was on a dyno, I’d add an easy 80-100 hp. The fellas above nailed it I think. The engine build has some good specs to it.

 

[rmchrgr]

Was the engine run on the dyno with the Sniper? If so, what kind of tune did it have? Is the Sniper controlling timing? If it’s only running in the initial ‘Wizard’ set up then there could likely be power left on the table.

 

[jcolman]

Was the engine run on the dyno with the Sniper? If so, what kind of tune did it have? Is the Sniper controlling timing? If it’s only running in the initial ‘Wizard’ set up then there could likely be power left on the table.

Yes, the sniper is on the car along with hyperspark so the system controls timing as well. The shop did a custom tune for me. They got an additional 20hp over what the original wizard set up was.

 

[512Stroker]

If anyone is interested, here's the dyno sheet along with what I know about this motor. Dyno session was run with fresh plugs and oil change.

340 blueprinted and balanced. .30 over. TRW flat top pistons. Mopar steel crank, Mopar performance rods. ARP fastners. Holley Sniper EFI with Hyperspark distributor. Edlebrock aluminum heads. Weiand Stealth dual plane Intake. Competition cams hydraulic roller cam. 490/490 lift, 262 duration. 10.5-1 CR. MSD Blaster SS coil. MSD 6AL ignition. 8mm plug Wires. Aluminum radiator. 6-Blade aluminum cooling fan. Hooker ceramic coated long tube headers with X crossover. 2.5” Pypes Turbo mufflers. Vibrant Ultra quiet resonators.

Trade in those Turbo muffs for some straight pass thru mufflers and you will see a noticeable increase in HP.

 

[jcolman]

Trade in those Turbo muffs for some straight pass thru mufflers and you will see a noticeable increase in HP.

I originally had flow masters on the car but the "drone" at 1900 rpm was driving me crazy. Hence the reason for the Pypes and resonators.

 

[autoxcuda]

I originally had flow masters on the car but the "drone" at 1900 rpm was driving me crazy. Hence the reason for the Pypes and resonators.

Sounds like you drive your car on the highway and spend some time in it. Nice!

 

[jcolman]

Sounds like you drive your car on the highway and spend some time in it. Nice!

That's what I wanted in a muscle car. However I don't really drive it all that much now since it's so hot. In fact, I have it up for sale. I decided that I would rather have a really nice daily driver so the Duster and my DD are up for sale.

 

[Rat Bastid]

What you posted was likely what's called "advertised" duration...
But we all want is the best of both worlds where it idols nice and smooth but has power like a dragster...
Also keeping in mind that Dinos are just a tool for tuning... Dinos can be different from each other but the thing they have in common is they give you a baseline reading and then you can improve from that baseline or unimprove through adjustments... The chassis Dyno like you have gives pretty much a baseline with your whole combination of transmission gears rear end gears but still doesn't take an account for the weight of the car...
An engine dyno just gets the engine and it's best performance..
That's why nothing beats a real world test like taking it to the track and getting a time slip... That's where it counts anyways... You try tuning the carburetor a little bit and get another time slip dry some different timing and get another time slip....

And you have personal experience to back all of this up?

 

[MOPAROFFICIAL]

I just got my 340 powered car back from the shop after a chassis dyno tune. It made 258 hp and 293 lbs torque. (air temp was 90* and 41% humidity) I was a bit disappointed at those numbers but the shop owner did a good job of explaining how much actual loss occurs between "crank HP" numbers and "real world" numbers to the rear wheels. He said that he's seen a lot of deflated egos from customers who thought their "mega" engine should be producing more HP after seeing the chassis dyno results. He went on to say that the "15% " loss on a chassis dyno is a myth and that the actual percentage can be much higher.

That torque number is spot on.
The operator is correct the Lost varies and it's greater than 15% more than not.

 

[roccodart440]

i bought a blueprint engine in 2011 with 238/238 @50 thou cam , air gap, dyno'ed with 750 edelbrock and dyno sheet said 415 horsepower ,486 torque with stock magnum heads. i think intake manifold is the bottleneck

It is certainly one of them.

In my mopar dyno experience I have found a few trends that support one of our communities engine builders claims.

1. Mopar engine do not like restriction above the heads because the heads are the restriction.

2. They like bigger plenums and bigger carbs. EVERY time I have had a a mopar engine on the dyno, it liked a bigger plenum and a bigger carb.

I would almost guarantee that your engine would make more HP with an HVH siper sucker on that RPM intake. It would most likely respond well to a Victor intake. It would most likely respond well to more CFM or true CFM.

 

[12many]

How about an update on this 15 page thread.

 

[Jim Ward]

I took the motor to the shop that did the heads and they figured out some issues. First the distributor I used in the first session was junk and total advance was over 42 degrees, the spark plug gaps were way off with some as close as ten thousandths and with a proper tune including timing sweep and carb jetting it made 455 hp and 512 lb ft of torque.

 

[12many]

Been to the strip yet?

 

[Ironracer]

I took the motor to the shop that did the heads and they figured out some issues. First the distributor I used in the first session was junk and total advance was over 42 degrees, the spark plug gaps were way off with some as close as ten thousandths and with a proper tune including timing sweep and carb jetting it made 455 hp and 512 lb ft of torque.

Sweet Deal Man!

 

[Jim Ward]

No I haven’t even put the motor in the car. I raced my 72 this summer. I will have it going next spring if I can stop working on everyone else’s vehicles. I have a 73 blazer that I’m finishing a total restoration on for a very close friend of mine and then I need to strip and paint a 69 GTO for another friend.

 

[Brooks James]

If you were hoping for bigger numbers, based on 340 to 422, I saw a Dyno test where a 360 mag was stroked to 408, stroker kit only, all else the same. it only raised the hp 34 hp. Loosely, using a ratio, 340 to 422 would give about 54 hp. Put a 150 shot of nitrous on it.

 

[B3422w5]

If you were hoping for bigger numbers, based on 340 to 422, I saw a Dyno test where a 360 mag was stroked to 408, stroker kit only, all else the same. it only raised the hp 34 hp. Loosely, using a ratio, 340 to 422 would give about 54 hp. Put a 150 shot of nitrous on it.

I recently did this very thing went from 360 to 418.
swapped headers, cam, intake, carb, convertor, trans, etc over from 360 to 418
only difference was the 418 had more compression.
went from 11.26 to 10.77 ET. Half a second is a lot.
that is a whole bunch more than 34 horsepower.
I talked to Ken Hensley years ago about this( owner of Hensley performance, well known Mopar engine shop), and he said, all things being the same, he sees 3 to 4 tenths in ET going to the stroker. I have found that to be true in several combinations.
I suspect my 5 tenths in this case was the extra compression.

 

[CUDACOX]

I'm just jumping in here but, my 1968 318/390 stroker is 30 over. I think cam is 287/525, edlebrock heads out of the box, edlebrock performer intake, 750 quickfuel manual secondary,double pump, no choke. It made 450H.P. and 490 TQ.
Sorry, it's first coffee, I'm just thinking numbers are low with what you have. I hope you get it figured out.

 

[rumblefish360]

If you were hoping for bigger numbers, based on 340 to 422, I saw a Dyno test where a 360 mag was stroked to 408, stroker kit only, all else the same. it only raised the hp 34 hp. Loosely, using a ratio, 340 to 422 would give about 54 hp. Put a 150 shot of nitrous on it.

A video of “HotRod TV” perhaps?

What they did there on that video was just simply changed the rotating assembly from the OEM 5.9 to the 4.00 arm crank and pistons. The limitations on hp were due to nothing being changed except the rotating assembly. Stock cam, heads, etc…
from the base test pull they did.

The main pull you or anyone should have taken from that video is the stroker kit added on a lot of torque.

Adding high performance street parts or stepping up to racing intakes and big cams with aluminum heads, your still going to see the big torque gain along with the increased hp, but in a direct apples to orange comparison of a stock 360 to 408, the maximum hp achieved will show earlier on the stroker (or should!) and may not be such a huge divide on hp vs the torque.

It’s all build dependent.

 

[fishmens67]

I recently did this very thing went from 360 to 418.
swapped headers, cam, intake, carb, convertor, trans, etc over from 360 to 418
only difference was the 418 had more compression.
went from 11.26 to 10.77 ET. Half a second is a lot.
that is a whole bunch more than 34 horsepower.
I talked to Ken Hensley years ago about this( owner of Hensley performance, well known Mopar engine shop), and he said, all things being the same, he sees 3 to 4 tenths in ET going to the stroker. I have found that to be true in several combinations.
I suspect my 5 tenths in this case was the extra compression.

Probably picked up 60 -70 Hp, but lowered the HP per cubic inch number by a tad.
The 418 with more compression will likely respond well if you decide to make a few changes.
5 tenths is very respectful for just adding cubes and a little compression.

 

[Hot Metal]

Not been through all the posts and cannot offer any new answers that have not been given already apart from giving you the specs of a '72 340/416 demon that runs here in our NSS class as a comparison>
!0.1:1, stock 2.02 J heads,73cc, may have some clean up I don't know.
hyd.cam 475"/494" [email protected] specs.
1.5/8" hdrs, air gap, 750DP, locked timing@34
now runs a TR with 2x 650's, +2/10ths and mph.
according to weight mph and it hooks well its making around 415>425hp.
shifts@5500 traps@5900>6000.

 

[autoxcuda]

I'm just jumping in here but, my 1968 318/390 stroker is 30 over. I think cam is 287/525, edlebrock heads out of the box, edlebrock performer intake, 750 quickfuel manual secondary,double pump, no choke. It made 450H.P. and 490 TQ.
Sorry, it's first coffee, I'm just thinking numbers are low with what you have. I hope you get it figured out.

Seems close without more details of your motor.

32 cubic inch difference. Different dyno and no sheets on either dyno pull to compare.

 

[B3422w5]

Probably picked up 60 -70 Hp, but lowered the HP per cubic inch number by a tad.
The 418 with more compression will likely respond well if you decide to make a few changes.
5 tenths is very respectful for just adding cubes and a little compression.

couple changes are indeed in the works!

 

[Howard1784]

I would be pissed! Get a stock motor for cheap and add 100 shot and you'll have more Hp.

If it makes you feel better, my MP 380 hp in a 3480 lb duster doesnt go faster than 14s. $800 stall, tti headers and lower gears added. Did NO better than the stock reman 360, stock convertor and non posi gears. I WASTED all that money for nothing and only get 9 miles per gallon. What a piece of garbage!

 

[Jim Ward]

Here is the best pull with the first dyno with the orange highlighter. The second is the best pull with 34 degrees total timing and after tuning on the second session.